1. Field of the Invention
The present invention relates to new pyrimidyl-thio-carboxanilides, several processes for their preparation and their use as herbicides.
2. Background Information
It is already known that certain carboxanilides have herbicidal properties (cf. R. Wegler "Chemie der Pflanzenuschutz-und Schadlingsbekampfungsmittel [The chemistry of plant-protection agents and pesticides]" Vol. 2, pages 311-314, Springer-Verlag, Berlin 1970). Thus, propion-3,4-dichloroanilide, for example, can be employed for combating weeds. The action of this compound is good, but some weeds are not always covered completely when small amounts are applied. In addition, the selectivity leaves something to be desired in some cases.
Furthermore, it is known that numerous 2-pyrimidinyl ethers and 2-pyrimidinyl thioethers are suitable as herbicides (cf. Japanese Preliminary Published Application No. 9,474/1967, U.S. Pat. No. 3,126,271 and U.S. Pat. No. 3,250,775). For example, 2-phenoxy-4,6-dimethyl-pyrimidine and 2-(4-chlorobenzylmercapto)-4,6-dimethyl-pyrimidine can be used to combat weeds. The herbicidal potency of these substances is, however, not always adequate.
Furthermore, it is known that lower acyl derivatives of 4-pyridyloxy-(or thio)-anilines have herbicidal properties (cf. DE-OS (German Published Specification) No. 2,501,648, Japanese Preliminary Published Application No. 55/122,763 and Japanese Preliminary Published Application No. 56/123,970). In addition, acyl derivatives of 4-pyrimidyloxy-anilines which are active as herbicides and which are substituted in the 5-position of the pyrimidyl radical by halogen or trifluoromethyl, but do not contain substituents in the 4 and 6 positions, are also known (cf. Japanese Preliminary Published Application No. 56/029,576). However, the effectiveness of these substances is not always satisfactory for practical purposes.